David Foster Wallace used his prodigious gifts as a writer — his manic, exuberant prose, his ferocious powers of observation, his ability to fuse avant-garde techniques with old-fashioned moral seriousness — to create a series of strobe-lit portraits of a millennial America overdosing on the drugs of entertainment and self-gratification, and to capture, in the words of the musician Robert Plant, the myriad “deep and meaningless” facets of contemporary life.

A prose magician, Mr. Wallace was capable of writing — in his fiction and nonfiction — about subjects from tennis to politics to lobsters, from the horrors of drug withdrawal to the small terrors of life aboard a luxury cruise ship, with humor and fervor and verve. At his best he could write funny, write sad, write sardonic and write serious. He could map the infinite and infinitesimal, the mythic and mundane. He could conjure up an absurd future — an America in which herds of feral hamsters roam the land — while conveying the inroads the absurd has already made in a country where old television shows are a national touchstone and asinine advertisements wallpaper our lives. He could make the reader see state-fair pigs that are so fat they resemble small Volkswagens; communicate the weirdness of growing up in Tornado Alley, in the mathematically flat Midwest; capture the mood of Senator John McCain’s old ”straight talk” campaign of 2000.

Mr. Wallace, who died Friday night at his home in Claremont, Calif., at 46, an apparent suicide, belonged to a generation of writers who grew up on the work of Thomas Pynchon, Don DeLillo and Robert Coover, a generation that came of age in the ’60s and ’70s and took discontinuity for granted. But while his own fiction often showcased his mastery of postmodern pyrotechnics — a cold but glittering arsenal of irony, self-consciousness and clever narrative high jinks — he was also capable of creating profoundly human flesh-and-blood characters with three-dimensional emotional lives. In a kind of aesthetic manifesto, he once wrote that irony and ridicule had become “agents of a great despair and stasis in U.S. culture” and mourned the loss of engagement with deep moral issues that animated the work of the great 19th-century novelists.

For that matter, much of Mr. Wallace’s work, from his gargantuan 1996 novel “Infinite Jest” to his excursions into journalism, felt like outtakes from a continuing debate inside his head about the state of the world and the role of the writer in it, and the chasm between idealism and cynicism, aspirations and reality. The reader could not help but feel that Mr. Wallace had inhaled the muchness of contemporary America — a place besieged by too much data, too many video images, too many high-decibel sales pitches and disingenuous political ads — and had so many contradictory thoughts about it that he could only expel them in fat, prolix narratives filled with Möbius strip-like digressions, copious footnotes and looping philosophical asides. If this led to self-indulgent books badly in need of editing — “Infinite Jest” clocked in at an unnecessarily long 1,079 pages — it also resulted in some wonderfully powerful writing.

He could riff ingeniously about jailhouse tattoos, videophonic stress and men’s movement meetings. A review of a memoir by the tennis player Tracy Austin became a meditation on art and athletics and the mastery of one’s craft. A review of a John Updike novel became an essay on how the “brave new individualism and sexual freedom” of the 1960s had devolved into “the joyless and anomic self-indulgence of the Me Generation.”

Although his books can be uproariously, laugh-out-loud funny, a dark threnody of sadness and despair also runs through Mr. Wallace’s work. He said in one interview that he set out with “Infinite Jest” “to do something sad,” and that novel not only paints a blackly comic portrait of an America run amok, but also features a tormented hero, who is reeling from his discovery of his father’s bloody suicide — his head found splattered inside a microwave oven. Other books too depict characters grappling with depression, free-floating anxiety and plain old unhappiness. One of the stories in “Oblivion” revolved around a cable TV startup called “the Suffering Channel,” which presented “still and moving images of the most intense available moments of human anguish.”

Like Mr. DeLillo and Salman Rushdie, and like Dave Eggers, Zadie Smith and other younger authors, Mr. Wallace transcended Philip Rahv’s famous division of writers into “palefaces” (like Henry James and T. S. Eliot, who specialized in heady, cultivated works rich in symbolism and allegory) and “redskins” (like Whitman and Dreiser, who embraced an earthier, more emotional naturalism). He also transcended Cyril Connolly’s division of writers into “mandarins” (like Proust, who favored ornate, even byzantine prose) and “vernacular” stylists (like Hemingway, who leaned toward more conversational tropes). An ardent magpie, Mr. Wallace tossed together the literary and the colloquial with hyperventilated glee, using an encyclopedia of styles and techniques to try to capture the cacophony of contemporary America. As a result his writing could be both brainy and visceral, fecund with ideas and rich with zeitgeisty buzz.
Over the years he threw off the heavy influence of Mr. Pynchon that was all too apparent in “The Broom of the System” (1987) — which, like “The Crying of Lot 49,” used Joycean word games and literary parody to recount the story of a woman’s quest for knowledge and identity — to find a more elastic voice of his own in “Infinite Jest.” That novel used three story lines — involving a tortured tennis prodigy, a former Demerol addict and Canadian terrorists who want to get their hands on a movie reputed to be so entertaining it causes anyone who sees it to die of pleasure — to depict a depressing, toxic and completely commercialized America. Although that novel suffered from a lack of discipline and a willful repudiation of closure, it showcased Mr. Wallace’s virtuosity and announced his arrival as one of his generation’s pre-eminent talents.

Two later collections of stories — “Brief Interviews With Hideous Men” (1999) and “Oblivion” (2004), which both featured whiny, narcissistic characters — suggested a falling off of ambition and a claustrophobic solipsism of the sort Mr. Wallace himself once decried. But his ventures into nonfiction, “A Supposedly Fun Thing I’ll Never Do Again” (1997) and “Consider the Lobster” (2005), grounded his proclivity for meandering, stream-of-consciousness musings in sharp magazine assignments and reportorial subjects, and they evinced the same sort of weird telling details and philosophical depth of field as his most powerful fiction. They reminded the reader of Mr. Wallace’s copious gifts as a writer and his keen sense of the metastasizing absurdities of life in America at a precarious hinge moment in time.

There are few subjects more timely than the one tackled by Susan Jacoby in her new book, “The Age of American Unreason,” in which she asserts that “America is now ill with a powerful mutant strain of intertwined ignorance, anti-rationalism and anti-intellectualism.”

For more than a decade there have been growing symptoms of this affliction, from fundamentalist assaults on the teaching of evolution to the Bush administration’s willful disavowal of expert opinion on global warming and strategies for prosecuting the war in Iraq. Conservatives have turned the term “intellectual,” like the term “ liberal,” into a dirty word in politics (even though neo-conservative intellectuals played a formative role in making the case for war against Iraq); policy positions tend to get less attention than personality and tactics in the current presidential campaign; and the democratizing influence of the Internet is working to banish expertise altogether, making everyone an authority on everything. Traditional policy channels involving careful analysis and debate have been circumvented by the Bush White House in favor of bold, gut-level calls, and reasoned public discussions have increasingly given way to noisy partisan warfare among politicians, commentators and bloggers alike…

As Ms. Jacoby sees it, there are several key reasons for “the resurgent American anti-intellectualism of the past 20 years.” To begin with, television, video games and the Internet have created a “culture of distraction” that has shortened attention spans and left people with “less time and desire” for “two human activities critical to a fruitful and demanding intellectual life: reading and conversation.”

The eclipse of print culture by video culture began in the 1960s, Ms. Jacoby argues, adding that the ascendance of youth culture in that decade also promoted an attitude denigrating the importance of tradition, history and knowledge.

By the ’80s, she goes on, self-education was giving way to self-improvement, core curriculums were giving way to classes intended to boost self-esteem, and old-fashioned striving after achievement was giving way to a rabid pursuit of celebrity and fame. The old middlebrow culture, which prized information and aspiration — and which manifested itself, during the post-World War II years, in a growing number of museums and symphony orchestras, and a Book-of-the-Month club avidity for reading — was replaced by a mass culture that revolved around television and blockbuster movies and rock music.

It was also in the ’60s, Ms. Jacoby writes, that a resurgent fundamentalism “received a jolt of adrenaline from both the civil rights laws” in the early years of that decade and the later “cultural rebellions.” She succinctly records the long history of fundamentalism in America, arguing that poorly educated settlers on the frontier were drawn to religious creeds that provided emotional comfort without intellectual demands, just as “the American experiment in complete religious liberty led large numbers of Americans to embrace anti-rational, anti-intellectual forms of faith.”